1. Field of the Invention
This invention relates to a multiplexer and multiplexing method for use with the same.
2. Description of the Related Art
In a liquid crystal display employing dot inversion techniques, a multiplexer is applied to transmit alternately positive and negative voltages to each pixel electrode of the liquid crystal display to achieve voltage inversion.
Referring to FIG. 1, a conventional multiplexer includes a first input terminal (IN1) adapted for receiving a first voltage (V1), a second input terminal (IN2) adapted for receiving a second voltage (V2) less than the first voltage (V1), an output terminal (OUT), a first switch 11 coupled between the first input terminal (IN1) and the output terminal (OUT), and a second switch 12 coupled between the second input terminal (IN2) and the output terminal (OUT). Each of the first and second switches 11, 12 is operable between an ON-state and an OFF-state.
The conventional multiplexer is operable between a first mode and a second mode. When the conventional multiplexer is in the first mode, the first and second switches are in the ON-state and the OFF-state, respectively, such that the first voltage (V1) is transmitted to the output terminal (OUT) through the first switch 11. In this case, the voltage across the second switch 12 is substantially equal to a difference between the first and second voltages (V1, V2), i.e., V1−V2. When the multiplexer is in the second mode, the first and second switches are in the OFF-state and the ON-state, respectively, such that the second voltage (V2) is transmitted to the output terminal (OUT) through the second switch 12. In this case, a voltage across the first switch 11 is substantially equal to the difference between the first and second voltages (V1, V2), i.e., V1−V2.
When the difference between the first and second voltages (V1, V2), i.e., V1−V2, is larger, the first and second switches 11, 12 are required to have a higher endure voltage so as to prevent damage thereto. Alternatively, the first and second switches 11, 12 are required to be fabricated through a high voltage semiconductor process, thereby resulting in relatively high costs.